Field of the Disclosure
The disclosure relates to a method for retransmitting packet, and more particularly, relates to a method for retransmitting packet based on network topology information, a data server using the same and a packet retransmitting system.
Description of Related Art
Under the existing network environment for multimedia data transmission, a network multicast method of the network communication technology is usually required to play multimedia data in real-time for multiparty. The so-called group broadcasting is to simultaneously transmit the same data to multiple receiver hosts that require said data. The hosts belong to the same group may be distributed over different networks to possibly include the same network address, and each of the hosts may join or leave one specific group freely. Accordingly, as compared to the unicast technique which only conducts transmission to one single network node each time, the network multicasting technique is capable of further reducing usage for both network bandwidth and network addresses.
On the other hand, in the wireless network environment, due to problems such as multipath fading and interference in the wireless channel, network packet loss often occurs and leads to a packet retransmission. In the existing technologies, owing to lack of consideration for the connection relation between the nodes in the wireless LAN, retransmitting missing packet by multicasting may cause a massive amount of transmissions for invalid and redundant packets. Such phenomenon not only occupies the network bandwidth and increases a number of times for conducting the packet retransmission but also results in packet loss at destination ends due to the packet collision. Accordingly, it is necessary to provide a method for retransmitting packet that is capable of improving an efficiency of the packet retransmission.